Dry grind biochemical production process and system with front end milling method

Abstract

A dry grind biochemical production process and system with front end milling method is provided for improving biochemical and/or by-product yields, such as oil and/or protein yields. In one example, the process includes grinding corn kernels into particles then mixing the corn particles with a liquid to produce a slurry including oil, protein, starch, fiber, germ, and grit. Thereafter, the slurry is subjected to a front end milling method, which includes separating the slurry into a solids portion, including fiber, grit, and germ, and a liquid portion, including oil, protein, and starch, then milling the separated solids portion to reduce the size of the germ and grit and release bound starch, oil, and protein from the solids portion. The starch is converted to sugar, and a biochemical is produced therefrom then recovered. Also, the fiber can be separated and recovered. Oil and protein may be separated and recovered as well.

What is claimed is: 
     
         1 . A dry grind biochemical production process, the process comprising:
 grinding corn kernels into particles;   mixing the corn particles with a liquid to produce a slurry including oil, protein, starch, fiber, germ, and grit;   subjecting the slurry to a front end milling method, which comprises:
 separating the slurry into a solids portion, including fiber, grit, and germ, and a liquid portion, including oil, protein, and starch; and 
 milling the separated solids portion to reduce the size of the germ and grit and release bound starch, oil, and protein from the solids portion; 
   converting the starch to sugar;   producing a biochemical from the sugar and recovering the biochemical.   
     
     
         2 . The process of  claim 1  further comprising separating and recovering the fiber. 
     
     
         3 . The process of  claim 2  wherein separating and recovering the fiber comprises separating and recovering the fiber prior to producing the biochemical. 
     
     
         4 . The process of  claim 1  wherein separating and recovering the fiber comprises separating the fiber after producing the biochemical, subjecting the fiber to a caustic treatment, and recovering the treated fiber. 
     
     
         5 . The process of  claim 1  further comprising, prior to producing the biochemical from the sugar and recovering the biochemical, separating and recovering the oil from the liquid portion. 
     
     
         6 . The process of  claim 5  wherein separating and recovering oil from the liquid portion includes extracting oil via solvent extraction. 
     
     
         7 . The process of  claim 1  further comprising, prior to producing the biochemical from the sugar and recovering the biochemical, combining the milled solids portion with the liquid portion. 
     
     
         8 . The process of  claim 1  wherein the liquid defines a counter current wash, which mixes with the corn particles to produce the slurry. 
     
     
         9 . The process of  claim 1  wherein subjecting the slurry to the front end milling method further comprises, after milling the separated solids portion, separating the milled solids portion into a second solids portion, including fiber, grit, and germ, and a second liquid portion, including oil, protein, and starch. 
     
     
         10 . The process of  claim 9  wherein subjecting the slurry to the front end milling method further comprises, after separating the milled solids portion into the second solids portion and the second liquid portion, separating the solids portion into a third solids portion, including fiber, grit, and germ, and a third liquid portion, including oil, protein, and starch. 
     
     
         11 . The process of  claim 10  further comprising separating and recovering the oil from the third liquid portion prior to producing the biochemical from the sugar and recovering the biochemical. 
     
     
         12 . The process of  claim 9  further comprising milling the second solids portion to reduce the size of the germ and grit and release bound starch, oil, and protein from the fiber. 
     
     
         13 . The process of  claim 12  wherein after milling the separated second solids portion, separating the milled second solids portion into a third solids portion, including fiber, grit, and germ, and a third liquid portion, including oil, protein, and starch. 
     
     
         14 . The process of  claim 13  further comprising milling the third solids portion to reduce the size of the germ and grit and release bound starch, oil, and protein from the fiber. 
     
     
         15 . The process of  claim 9  wherein the second liquid portion defines the liquid, which mixes with the corn particles in a counter current set-up to produce the slurry. 
     
     
         16 . The process of  claim 1  further comprising separating and recovering the protein. 
     
     
         17 . The process of  claim 16  wherein separating and recovering the protein comprises separating and recovering the protein after recovering the biochemical. 
     
     
         18 . A system for dry grind biochemical production, the system comprising:
 a grinding device, which grinds corn kernels into particles;   a slurry tank in which the corn particles mix with a liquid to produce a slurry including oil, protein, starch, fiber, germ, and grit;   a first dewatering device, which separates the slurry into a solids portion, including fiber, grit, and germ, and a liquid portion, including oil, protein, and starch;   a size reduction device, which follows the first dewatering device and reduces the size of the germ and grit of the solids portion and releases bound starch, oil, and protein from the solids portion;   at least one holding tank, which aids in converting the starch to sugar;   a fermenter to produce a biochemical from the sugar and a still to recover the biochemical; and   a second dewatering device, which separates and recovers the fiber.   
     
     
         19 . A dry grinding biochemical production process, the process comprising:
 grinding corn kernels into corn particles;   mixing the corn particles with a liquid to form a slurry;   reducing an amount of the liquid from the slurry to form a wet cake; and   milling the wet cake.   
     
     
         20 . The process of  claim 19  further comprising producing a biochemical from the sugar.